001/**
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.camel.model;
018
019import java.util.ArrayList;
020import java.util.List;
021import javax.xml.bind.annotation.XmlAccessType;
022import javax.xml.bind.annotation.XmlAccessorType;
023import javax.xml.bind.annotation.XmlElementRef;
024
025import org.apache.camel.Expression;
026import org.apache.camel.Predicate;
027import org.apache.camel.Processor;
028import org.apache.camel.builder.ExpressionClause;
029import org.apache.camel.model.language.ExpressionDefinition;
030import org.apache.camel.processor.FilterProcessor;
031import org.apache.camel.spi.Required;
032import org.apache.camel.spi.RouteContext;
033
034/**
035 * A base class for nodes which contain an expression and a number of outputs
036 *
037 * @version
038 */
039@XmlAccessorType(XmlAccessType.FIELD)
040public class ExpressionNode extends ProcessorDefinition<ExpressionNode> {
041    @XmlElementRef
042    private ExpressionDefinition expression;
043    @XmlElementRef
044    private List<ProcessorDefinition<?>> outputs = new ArrayList<ProcessorDefinition<?>>();
045
046    public ExpressionNode() {
047    }
048
049    public ExpressionNode(ExpressionDefinition expression) {
050        this.expression = expression;
051    }
052
053    public ExpressionNode(Expression expression) {
054        if (expression != null) {
055            setExpression(ExpressionNodeHelper.toExpressionDefinition(expression));
056        }
057    }
058
059    public ExpressionNode(Predicate predicate) {
060        if (predicate != null) {
061            setExpression(ExpressionNodeHelper.toExpressionDefinition(predicate));
062        }
063    }
064
065    @Override
066    public String getShortName() {
067        return "exp";
068    }
069
070    public ExpressionDefinition getExpression() {
071        return expression;
072    }
073
074    @Required
075    public void setExpression(ExpressionDefinition expression) {
076        this.expression = expression;
077    }
078
079    @Override
080    public List<ProcessorDefinition<?>> getOutputs() {
081        return outputs;
082    }
083
084    public void setOutputs(List<ProcessorDefinition<?>> outputs) {
085        this.outputs = outputs;
086    }
087
088    @Override
089    public boolean isOutputSupported() {
090        return true;
091    }
092
093    @Override
094    public String getLabel() {
095        if (getExpression() == null) {
096            return "";
097        }
098        return getExpression().getLabel();
099    }
100
101    /**
102     * Creates the {@link FilterProcessor} from the expression node.
103     *
104     * @param routeContext  the route context
105     * @return the created {@link FilterProcessor}
106     * @throws Exception is thrown if error creating the processor
107     */
108    protected FilterProcessor createFilterProcessor(RouteContext routeContext) throws Exception {
109        Processor childProcessor = createOutputsProcessor(routeContext);
110        return new FilterProcessor(createPredicate(routeContext), childProcessor);
111    }
112
113    /**
114     * Creates the {@link Predicate} from the expression node.
115     *
116     * @param routeContext  the route context
117     * @return the created predicate
118     */
119    protected Predicate createPredicate(RouteContext routeContext) {
120        return getExpression().createPredicate(routeContext);
121    }
122
123    @Override
124    protected void configureChild(ProcessorDefinition<?> output) {
125        // reuse the logic from pre create processor
126        preCreateProcessor();
127    }
128
129    @Override
130    protected void preCreateProcessor() {
131        Expression exp = expression;
132        if (expression != null && expression.getExpressionValue() != null) {
133            exp = expression.getExpressionValue();
134        }
135
136        if (exp instanceof ExpressionClause) {
137            ExpressionClause<?> clause = (ExpressionClause<?>) exp;
138            if (clause.getExpressionType() != null) {
139                // if using the Java DSL then the expression may have been set using the
140                // ExpressionClause which is a fancy builder to define expressions and predicates
141                // using fluent builders in the DSL. However we need afterwards a callback to
142                // reset the expression to the expression type the ExpressionClause did build for us
143                expression = clause.getExpressionType();
144            }
145        }
146
147        if (expression != null && expression.getExpression() == null) {
148            // use toString from predicate or expression so we have some information to show in the route model
149            if (expression.getPredicate() != null) {
150                expression.setExpression(expression.getPredicate().toString());
151            } else if (expression.getExpressionValue() != null) {
152                expression.setExpression(expression.getExpressionValue().toString());
153            }
154        }
155    }
156}